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Earning their 5-year pins |
Two days before officially moving out from the DC area last fall, Bea went to spend half a day finishing up earning her final Master Gardener volunteer hours at a local public garden. She does things like this just to check things off her to-do-lists. This morning of volunteer work gave her enough hours to earn her 5-year pin at the annual Christmas party, which of course meant driving back up to DC and a midnight drive home, but Bea was happy so it was worth it! Plus that party always features LOTS of delicious free food. Definitely worth it.
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Well, hello there, leftover raspberries! |
Anyway, the other result of this morning of volunteer work was that Bea earned us 100+ free raspberry plants! (Who knew that we needed so many?!) Apparently, the volunteer task that day was thinning out existing plants, and after filling in gaps they still ended up with a wheelbarrow full of unneeded plants that were bound for the compost until Bea stepped in to save them.
Unfortunately, what with the move and all, the poor plants ended up sitting around for a month before we had a chance to do anything with them. Then right before we left on our Christmas adVANture, we had a week of unseasonably beautiful weather and Bea decided it was time we dug 150' of trenches, build a dozen raspberry trellises, and got these plants in the ground -- all in less than 3 days!
Bea did some online research and designed our trellises based on a sort of average between various pieces of dissenting advice available from blogs and extension services up and down the east coast. We documented our process and we'll follow up next year with an update on how they actually serve once our plants (hopefully!) grow.
How to Build Raspberry Trellises
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Measure once... |
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Measure twice! |
Step 1: Figure out how many trellises you'll need & stake out your area.
We decided to plant three 50' rows of raspberries and space the trellises 16' 8" apart [50'/3] based on reading recommended trellis spacing of anywhere from 12-25' apart within rows. 16'8" seemed like a good average. So, we'd need a total of a dozen trellises.
We wanted them to line up with our future hoophouse (also 50' long) and also with a driveway that runs alongside our field so that they'll look neat when the Googlemaps satellite snaps its next photo! So we spent quite a bit of time with 100' tape measures, string, squares, calculators, and rebar scrap stakes making sure everything was lined up before ever starting the building portion of this project. We spaced our rows 7' apart so we can still get a lawn mower between them and so the canes don't create a complete thicket in the summer!
Step 2: Acquire lumber.
While cedar or another hardwood would be an optimal choice for trellises, we are still on a restricted budget so we went with treated lumber. Since lumber is treated with chemicals (sometimes including arsenic, although
this article indicated that's no longer accepted practice), it's not generally recommended for edible garden applications like raised beds -- but we are burying these posts into a very wet soil and so in our case untreated wood just wouldn't last. So for each PAIR of trellises, we bought:
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Our compost arrives! |
You'll also need to buy some concrete -- we used (3) 60# bags for installing our 12 trellises. [Note: don't forget to double-check your math before hauling home 3x as much concrete as you actually need -- unloading it -- not needing it -- loading it back up -- and then back to the store. While it's returnable if it didn't get wet, this makes for more of a workout than most people care to pursue!]
You'll also need a load of compost for amending the soil while you plant your raspberries. We ordered a dumptruck-full because we'll need it for our garden and future hoophouse as well.
Step 3: Mark your cuts and notches.
We decided to use a half-lap joint to connect the 2x4 cross-pieces to the 4x4 upright. Basically this means cutting a notch in the 4x4 that's the correct size to accept the 2x4 and sit flush. This will keep any rainwater from sitting directly on the joint & it looks nice too.
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Mark out the notches |
For the cross-pieces, we cut to 18" and 30" so that we could get 4 pieces out of each 8' 2x4. We decided to position them 42" and 66" when measuring up from the bottom of the 4x4, with the wider crosspiece sitting above the smaller one. The wires extending from the shorter crosspiece should catch the new/early growth on the raspberry plants while the taller crosspieces will catch the canes when they're fully grown and producing berries. If these measurements seem tall, don't forget that the posts are going to be buried 18" in the ground so the final height of these crosspieces will be 2' and 4' above the ground. [Side note: if you wanted to conserve lumber, you could use 12' 4x4s cut in half and not have any extra post sticking up above the upper crosspiece. We thought it could be useful to have the extra in case we have to install bird netting in future so we stuck with 8' posts.]
To mark your cuts, just use a speed square to make straight lines and trace the lip of it around the corner on the post so your lines show at least 2 sides of the lap cut. You can trace out the 3rd side too if you want but it's not necessary.
Step 4: Cut up the crosspieces.
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Centering the placement of crosspieces |
A circular saw is easiest for this. Once you have a pile of short pieces, one person can go about measuring the center on each of these and marking out where the pieces should overlap in order to be centered. If cut accurately, the marks on the shorter piece will be at 7 1/4" and 10 3/4", and for the longer pieces 13 1/4" and 16 3/4". (Basically you're taking the center marks of 9" and 15" and adding/subtracting half the width of the 4x4 [3.5"/2 = 1.75"]. You could also just eyeball this but we're kind of OCD!)
Step 5: Notch your posts.
You'll need a reciprocating saw (sawzall) with a somewhat flexible wood blade. It's easier to use a circular saw for the straight cuts but a sawzall will do that too if you have a steady hand. First, cut along the two sides.
Then, come back with your sawzall to cut a gentle diagonal curve from one corner down to the bottom of the lap and across. Then take your sawzall back across the bottom of the lines to complete the lap. Keep a test 2x4 handy to make sure they fit & make additional adjustment cuts as needed. The goal is to have the cross-pieces sit square and as snugly as possible so rain doesn't get into the joint.
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Square! |
Step 6: Screw everything together.
Make sure to use galvanized screws which are rated for outdoor use! We attached 3 to each joint in a triangle pattern for strength.
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One completed trellis. 11 more to go! |
Step 7: Prepare your trenches & post-holes.
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“I love post-holing!" |
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18" down is a long way in clay soil! |
So while one person was making all those notch cuts, the other person can be digging & amending trenches, plus digging post holes. In our case, Bea really likes digging post holes for some reason, so she dug down 18" with a post-hole-digger. (Check your local building codes for the depth of your frost-line.) We used quite a lot of string and rebar scraps to stake everything out and make sure these holes were in line -- the “measure twice, cut once!" rule applies to digging too!
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1st trench complete |
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Spreading out the compost |
We removed sod and dug trenches 1' wide and 1' deep with a spading fork & shovel, then shoveled in 4" of finished compost, raked the soil we had removed back on top, mixed it up with the compost, and then raked everything flat. It's going to be a lot easier to prepare the ground at the same time as you're installing your trellises so suck it up and prepare for a good few days of hard work!
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Raking soil back on top |
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Compost adds nutrients to our mostly-clay soil |
Step 8: Install the trellises!
Our groundwater is apparently very high and so our holes started filling with water. We found small rocks and put one or two down in each hole just so the bottom of the post wouldn't be sitting straight in water. Putting a rock in the bottom of post-holes isn't a bad idea in any case.
So once you're ready, drop your trellis down into the post-hole and have one person check that it's plumb. A post-level is a great tool to make this easy as you can check 2 directions at one time. Make sure it's straight in line with the others in its row, and if you're a perfectionist, you can ensure that it's in line with the other rows too.
While one person holds the post in position, the other can pour concrete down into the hole all around the post. We chose to dry-pack the concrete which means taking advantage of groundwater or impending rain to set the cement for you rather than mixing it up beforehand. Dry-packing is a lot less messy and certainly quicker, as long as you don't live in a desert or somewhere really dry. We tamped the concrete down around the post with a garden trowel and made sure to fill the hole all the way up level with the surrounding soil.
If your trellises are wobbly at all you may wish to stake them so they don't move during the concrete-curing process, but ours seemed sturdy so we just left them as-is. After a couple of days they were solid.
Step 9: Plant your raspberries!
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Soak in water before planting |
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Space 2'-3' apart |
If you're careful not to bump into your trellises, you can put the plants in the ground the same day as you install your trellises. If you're clumsy, you can wait until the trellises' concrete bases are cured and come back to plant then. Red raspberries need spacing 2' within rows and black raspberries need to be 3' apart. Soak your plants in a bucket of water before planting and water thoroughly as soon as they're planted if rain isn't imminent. Mulch heavily with leaves for the winter.
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Patience... |
Step 10: Attach guide wires
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Hardware for the catchwires |
Sometime before our plants start growing in spring, we'll attach guide wires to the end of each crosspiece. We bought a spool of galvanized electric fence wire which will run from one end to the other (4 runs per row -- one on each crosspiece end). We'll run the wire through weatherproof eyehooks attached to the end of each crosspiece, and each end will also have a turnbuckle on it so we'll be able to get the wire pretty tight. We'll update this with a picture once this part of the assemblage is installed!
In the end...
The two of us were able to finish this project by working (3) 6-hour days, installing approximately one 50' row of raspberries per day. You don't strictly need ~100 raspberry plants for a family of 2. Bea has ideas that she will be able to load up our freezer and also make a lot of jam and friends with these berries. We'll update with a raspberries post next summer with how it actually works out for us!
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Our completed raspberry field! |